Device for locking a front end of a shaft in a spear gun for scuba divers

ABSTRACT

A device is provided for locking a front end of a shaft for a spear gun. The device comprises a bridge-shaped element extending crosswise over a distal end of the gun with a substantially U-shaped nosepiece connected to the distal end and revolving relatively freely about a crosswise axis thereof. The nosepiece includes at least two arms connected respectively to ends of a relatively elastic cable that may be tensioned against a rear end of the shaft, when the shaft is placed on a support surface along the body of the gun. The bridge element is attached to and integrally with the ends of the elastic cable and is placed at a selected distance from the support surface such that the shaft is retained against the surface when the spear is in a stowed or loaded position in the gun.

FIELD OF THE INVENTION

The present invention relates generally to fishing and underwater hunting and, more particularly, to weapons for use in scuba diving and the like.

BACKGROUND OF THE INVENTION

In conventional aquatic hunting, for instance, where the weapon of choice is typically a spear gun, various devices have been developed to hold a front end of the spear shaft in a selected position at a distal end of the gun until the trigger is pulled and the spear is launched towards the intended prey.

In one such known device, the distal end of the gun is fitted with a fixed bridge defining an axial seat in which the spear shaft engages, remaining in position until the gun is fired, despite any movement by the scuba diver. In this type of device, there is also a metal bar in the form of an arch, conventionally called the nosepiece, attached to the distal end of the gun, the substantially U-shaped arch having its open end facing the proximal end of the gun. The arch can rotate freely around the distal end of the gun and its two arms are attached to the ends of an elastic cable, generally made of rubber, which is first tensioned and then released to launch the spear shaft. Since the two ends of the elastic cable are fixed to the arms of the nosepiece, which is free to rotate around the distal end of the gun, when the elastic cable is released, it can rise away from the gun, and thus avoids obstructing the sliding movement of the spear shaft.

This first conventional system has the disadvantage of allowing the spear shaft some degree of slack inside the above-mentioned bridge, which prevents the scuba diver from taking an accurate aim.

A simplified version of the previous solution involves having the bridge at the distal end of the gun, while the ends of the elastic cable are connected directly, in a fixed position, to either side of the distal end of the gun.

In another known device of this type, no bridge is used and the front end of the spear shaft is held in position by the rope attached to the spear, which passes crosswise over the spear shaft, holding it against the end of the gun. The structural simplification involved in this solution is countered by the scuba diver having to adopt a more complicated procedure to load the gun.

In short, according to the known solutions, when there is a bridge, which facilitates the procedure for loading the spear, the end of the shaft is held in place by the bridge with an unavoidable degree of slack that reduces the accuracy of the scuba diver's aim if the diver changes position. On the other hand, eliminating the nosepiece makes it more complicated to load the spear.

OBJECTS AND SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a device for locking a front end of a shaft in a spear gun that eliminates slack inside the bridge at the distal end of the spear shaft and, thereby, allows the scuba diver to take accurate aim.

According to one aspect of the present invention, a locking device is provided for a front end of a shaft for a spear gun. The device preferably comprises a bridge-shaped element extending generally crosswise over a distal end of the gun with a substantially U-shaped nosepiece connected to the distal end so that the device may revolve about a selected crosswise axis. The nosepiece desirably includes at least two arms that are connected respectively to ends of a relatively elastic cable that may be tensioned against a rear end of the shaft, when the shaft is placed on a support surface along the body of the gun. The ends of the elastic cable are attached to and integrally with the bridge element, which is at a selected distance from the support surface such that the shaft is held or retained against the surface when the spear is in a stowed or loaded position in the gun.

BRIEF DESCRIPTION OF THE DRAWINGS

A specific, illustrative locking device, according to the present invention, is with reference to the accompanying drawings, in which:

FIG. 1 is a schematic side view of a distal end of a spear gun for scuba divers showing a locking device, according to one aspect of the present invention;

FIG. 2 is a sectional view, taken longitudinally, of a distal end of the gun illustrated in FIG. 1;

FIG. 3 is a front view of the gun shown in FIG. 1, from the direction of arrow F, with the spear in a stowed or loaded position;

FIG. 4 is a front view of the gun shown in FIG. 1, from the direction of arrow F, showing the spear in an operative position—immediately after firing the gun, before the spear has become detached from the gun.

Still other objects and advantages ofthe present invention will become apparent from the following description of the preferred embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and, more particularly, to FIGS. 1-4, there is shown generally a specific, illustrative locking device, according to various aspects of the present invention. In one embodiment, illustrated schematically in FIG. 1 a spear gun for scuba divers is provided, the gun having a distal end 1 and a shaft 2 of a spear mounted at the distal end. One of two ends 3 of a relatively elastic cable C extending along the body of the gun is tensioned by its engagement with a tooth provided on a rear portion of the shaft. Using a bushing 4, each end 3 ofthe elastic cable is joined axially to an arm 5 a of a nosepiece 5 that preferably has a relatively slender metallic arch mounted revolving/rotatably and crosswise to distal end 1 of the gun.

A bridge 6 is integrally attached in a crosswise position between the two bushings 4. The distance of the bridge 6 from the surface 1 a for supporting the shaft 2 at the distal end 1 is such that, when the spear is in the loaded position in the gun, the bridge 6 holds the shaft 1 against the gun, preventing any movement of the shaft. In other words, the distance between the bridge 6 and the supporting surface 1 a is essentially equal to the diameter of the shaft 2, so that when the spear is in the loaded position, the underside of the bridge 6 rests against the shaft 2, holding it in position against the supporting surface 1 a of the gun even if the scuba diver moves prior to firing the gun (see FIG. 3). When the gun is fired, the elastic cable C lifts away, together with the bushings 4 attached to its ends and the bridge 6 integrally connected thereto. As shown in FIG. 4, when the bridge 6 is lifted away, it releases the spear shaft 2, which is consequently launched unobstructed towards the prey.

From the above description, it is clear that the invention, which consists in the bridge being integrally to the nosepiece so that they rotate together when the previously tensioned elastic cable is released, fully achieves the previously-stated objects. In fact, this rotation increases the cross-section of the space where the spear shaft passes, thus allowing it to slide freely when it is fired; when in the loaded position, on the other hand, the bridge abuts against the spear shaft, thereby retaining it in a fixed position even if the scuba diver moves prior to firing the gun.

Various modifications and alterations to the invention may be appreciated based on a review of the disclosure. These changes and additions are intended to be within the scope and spirit of the invention as defined by the following claims. 

1. A device for locking the front end of the spear shaft in a fishing gun for scuba divers, comprising a bridge-shaped element extending crosswise over a distal end of the gun with a substantially U-shaped nosepiece connected to the distal end and revolving freely about a crosswise axis thereof, the nosepiece a plurality of arms connected respectively to ends of a relatively elastic cable that is tensioned against a rear end of the shaft, when the shaft is placed on a support surface along the body of the gun, wherein the bridge element is attached to and integrally with the ends of the elastic cable and is at a distance from the support surface such that it the shaft is retained against the surface when the spear is in a stowed or loaded position.
 2. The locking device set forth in claim 1, wherein the ends of the elastic cable are connected to corresponding terminal bushings attached to and integrally with the arms of the nosepiece, the bridge element being affixed to the bushings and extending crosswise from one to the other.
 3. The locking device set forth in claim 1, wherein the distance between the bridge element and the support surface is generally the same as the diameter of the shaft. 